I had that Fender 2x15 when I was a kid of 17....and used it through age 23 or so. I remember moving it around a lot myself, although it was a two-man job on stairs.
When I got my bass gear back from my parents' home at age 46, I swore to god that someone had hidden 30 pounds of lead somewhere in that 2x15 cab. I just didn't remember it being that HEAVY.
Of course, I'm completely out of shape and trying to work back in...starting to spend time on the elliptical and the weight machine downstairs. Fortunately my back is good, although all it takes is one careless lift and it reminds me I'm not 17 any more. My problem is feet...even with custom orthotics, I can walk about 9 holes (2.5 miles) and I'm hurting at that point. Too bad, because I used to spend a lot of time walking.
At least the 4x10 has rollers! It got them about 30 minutes after I picked it up at the store.